The invention relates to a guide rail assembly for drawers and including, for each side of the drawer, a supporting rail to be attached to the side of a body or article of furniture and a pull-out rail slideably mounted on the supporting rail. The load of the drawer is transmitted between the pull-out rail and the supporting rail by means of runner rollers and/or balls which are substantially in a horizontal plane and adjacently mounted in carriages. The supporting rail has a U-shaped channel with outwardly projecting horizontal marginal flanges on both sides thereof. Runner rollers or balls run in the U-shaped channel on one side of the supporting rail and run on the marginal flanges on the other side of the supporting rail. The pull-out rail is C-shaped and embraces the carriage.
Guide rail assemblies of the afore-mentioned kind are widely used in modern furniture construction, in particular in the construction of kitchen and office furniture. Such assemblies are designed to facilitate extraction and insertion of a drawer or shelf, to make these motions as smooth as possible and to prevent the drawer or shelf from tilting when it is partly extracted from or inserted into the body of the piece or article of furniture.
Guide rail assemblies should, apart from the aforementioned functions, fulfill further requirements. They should not, or should only slightly, reduce the loading capacity of the drawer, i.e. as little space as possible should be occupied by the guide rail assemblies with respect to the width or breadth of the drawer. Furthermore, it is advantageous for the carriage to be covered by the drawer to the greatest possible extent and thereby be protected against excessive ingress of dust. Thereby, not only appearance advantages but also a lengthened operational life of the guide rail assembly are obtained.
It is known to manufacture the side walls of the drawer from plastics material, for example by extrusion. It is further known to arrange the pull-out rails of the guide rail assembly in the drawer side walls, and it is also known to cover the pull-out rails and the carriages outwardly by means of a downwardly extending cover elements.
One example of a guide rail assembly in which the rails are arranged underneath the drawer bottom is described in AT-PS No. 362 899. A guide rail assembly of this kind has the advantage that it can be integrated into the piece of furniture in a very space-saving manner so that it requires no substantial space in the direction of the breadth of the drawer.
A pull-out guide assembly is known from DE-OS No. 35 40 787 which guarantees smooth running and good lateral guiding for heavy drawers. The rails of this assembly are fastenable to the piece of furniture in a very space-saving manner. In guide rail assemblies of this kind smooth running of a ball bearing guidance is combined with simple construction of a carriage guidance with cylindrical runner rollers.